import { getCurrentInstance, reactive, shallowRef, watchEffect } from 'vue';
import type { Ref } from 'vue';
interface Params {
	excludeListeners?: boolean;
	excludeKeys?: string[];
	excludeDefaultKeys?: boolean;
}

const DEFAULT_EXCLUDE_KEYS = ['class', 'style'];
const LISTENER_PREFIX = /^on[A-Z]/;

export function entries<T>(obj: Recordable<T>): [string, T][] {
	return Object.keys(obj).map((key: string) => [key, obj[key]]);
}

export function useAttrs(params: Params = {}): Ref<Recordable> | {} {
	const instance = getCurrentInstance();
	if (!instance) return {};

	const { excludeListeners = false, excludeKeys = [], excludeDefaultKeys = true } = params;
	const attrs = shallowRef({});
	const allExcludeKeys = excludeKeys.concat(excludeDefaultKeys ? DEFAULT_EXCLUDE_KEYS : []);

	// Since attrs are not reactive, make it reactive instead of doing in `onUpdated` hook for better performance
	instance.attrs = reactive(instance.attrs);

	watchEffect(() => {
		const res = entries(instance.attrs).reduce((acm, [key, val]) => {
			if (!allExcludeKeys.includes(key) && !(excludeListeners && LISTENER_PREFIX.test(key))) {
				acm[key] = val;
			}

			return acm;
		}, {} as Recordable);

		attrs.value = res;
	});

	return attrs;
}
